.......The 4th is actually a trunnion table, with one side bolting to an upright 4th axis and the other side on a pivot.
That's how my fourth is set up. The post processor makes my head hurt. I built a universal intake machining fixture for manual machining that has a sled/table with one end mounted in a rotary table and the other in pivot.......but all manual. Serves well for one-offs but wouldn't be the end of the world to manually reposition the 4th between ops on a 3-axis machine.
The CNC machine has 36" from the spindle nose to the table,
......I'm envious....that's a real machine.
.....so with a long drill I can drill at least through two of the throttle bores. Not sure if I can get three, or all four in one drilling operation, so if I can't, it will be drill two, rotate 180 degrees, and then drill the other two.
FWIW, coming from someone who has made many inline throttle bodies, other than set up reduction and convenience, I'd tell you not to go out of your way to drill them in one op. Trying to gun drill shaft holes of such a small diameter and length without very specialized machines, tooling, and fixturing, can be a very unrewarding exercise.
Even if they are machined to perfection through all bores as far as position and alignment, with throttle plates that are suitable fit to the bores, the throttle shafts will still be prone to binding due to thermal growth of the head versus shaft, mounting forces, and just how much things tend to move around on their own over time. I don't know how the original was set up, but I think I'd just plan to install a zero backlash coupling that can tolerate small misalignment and axial displacement between each bore, and call it a day.
All said, I'm certain much bigger machining challenges await with the block and other components. Definitely a man's sized job.
Best,
Kelly
